Alternative delivery of polio vaccines

Abstract

Since global polio eradication is coming up, there is an urgent need for an affordable inactivated polio vaccine (IPV) for its use in the post-eradication era. However, to reach the final goal of a polio-free world, it is believed that the routine use all live-attenuated oral poliovirus vaccines (OPV) should be discontinued, where the use of (Sabin) IPV is preferable in the period thereafter. A new generation of IPV should overcome the major drawbacks of OPV and should therefore ideally be administered through alternative (needle-free) delivery routes, provide mucosal immunity, and be affordable for low-income countries. In this review, we will discuss different alternative delivery routes for polio vaccines. First, we will focus on the mucosal vaccine delivery route, in which lessons learned from OPV are highlighted and the potential of nasal, sublingual and buccal delivery are described. Secondly, dermal delivery of polio vaccines, like using jet injection and microneedle approaches, is addressed. Finally, future perspectives, including the potential of improved vaccine formulations, the use of adjuvants and promising delivery systems are given.